Font size modulates saccade-target selection in Chinese reading

Abstract

In alphabetic writing systems, saccade amplitude (a close correlate of reading speed) is independent of font size, presumably because an increase in the angular size of letters is compensated for by a decrease of visual acuity with eccentricity. We propose that this invariance may (also) be due to the presence of spaces between words, guiding the eyes across a large range of font sizes. Here, we test whether saccade amplitude is also invariant against manipulations of font size during reading Chinese, a character-based writing system without spaces as explicit word boundaries for saccade-target selection. In contrast to word-spaced alphabetic writing systems, saccade amplitude decreased significantly with increased font size, leading to an increase in the number of fixations at the beginning of words and in the number of refixations. These results are consistent with a model which assumes that word beginning (rather than word center) is the default saccade target if the length of the parafoveal word is not available.

Saccade-target selection of dyslexic children when reading Chinese

“…Compared to Yan et al (2010), the average saccade amplitude in the present study was shorter, and there were more refixations. These results are in agreement with Shu et al (2011), who reported that saccade amplitude decreased and number of fixations at word beginnings increased significantly when parafoveal word length information was difficult to obtain. Nevertheless, our results suggest that saccade-target selection is still based on words for Chinese children, even though to a smaller extent.…”

Eye movement guidance in Chinese reading: Is there a preferred viewing location?

“…However, more recently, Yan, Kliegl, Richter, Nuthmann, and Shu (2010) reported some conflicting results relative to the initial studies. First, they found that the initial fixation on a word was more likely to fall on the characters at the beginning of a word, resulting in a PVL curve peaked at the beginning of a word when more than one fixation is made on a word (for similar results, see Shu, Zhou, Yan, & Kliegl, 2011). This pattern is consistent with findings from unspaced English reading (Rayner et al, 1998) and findings from Japanese reading (Kajii, Nazir, & Osaka, 2001).…”

Eye movement control in reading: Logographic Chinese versus alphabetic scripts

“…Indeed, Shu et al. () discovered that saccade amplitude decreased with increasing font size in reading Chinese, a result which was not found in alphabetic writing systems. Eye‐movement models of reading Chinese may thus need to incorporate a more flexible saccade‐targeting system.…”

“…When the launch site was far away from the next word, readers tended to fixate at the beginning of the word. In a subsequent study, Shu, Zhou, Yan, and Kliegl () discovered that there were also more fixations towards the beginning of the word when the font size was large, presumably because the information at the end of the word was not available for parafoveal processing. The authors interpreted their results as readers’ attempts to extract information about the word boundary in the parafovea, which would be more successful when the next word was completely located within the perceptual span of the reader (but see Li, Liu, & Rayner, , for an alternative explanation based on a combination of character‐based and word‐based processing).…”